The effect of light on the human body. The effect of light on the human body. Effects of daylight on circadian cycles

1. The amount of light (a lot!). No type of artificial light will provide the same illumination as a regular street.

2. Type of light, spectrum, UV. It is necessary and not necessary! Skin protection against photoaging.

3. Influence of light on performance.

4. Technologies: windows, architectural systems, the most advanced - optical fibers.

5. Gadgets (regular UV goggles)

There are five main mechanisms of action of daylight:

1. General effect on the nervous system, it maintains its rhythm of activity (learning, performance, tone, etc.).The psychophysiological effects of daylight include reducing the risk of seasonal depression, stress, overwork, improving performance, preventing mental and anxiety disorders.

3. The influence of illumination on vision and the processes of accommodation and adaptation, healthy light contributes topreservation of visual acuity in adults, correct formation of visual pathways in a child (artificial lighting cannot yet compete with daylight)

4. Maintenance of the "day-night" cycle: control of the body's internal clock (circadian rhythms) involved in the hormonal regulation of all organs and systems

5. Aesthetic aspect: general emotional support through contact with the outside world - a sense of time, weather changes, daytime and seasonal changes in landscapes, daylight - the simplest and most widely available means of dynamic aestheticization of the environment.

Healthy daylight at a glance.

Why do we lack light? Modern people spend 80-90% of the time indoors. , and the illumination in buildings is an order of magnitude less than on the street. Most of us develop a lack of daylight, which manifests itself in poor sleep, irritability, depression, and decreased immunity. Daylight supports the ability to learning... Daylight stimulates the production of serotonin in the human body. Daylight enhances working capacity person.

In most of our buildings, the internal microclimate is uncomfortable for humans due to insufficient illumination of the premises. The best light for vision is natural sunlight. The healthiest option is a little scattered daylight white.

It was found that not all solar radiation passes through the glazed surface of the window. Part of it is reflected, part is absorbed by glass and window frames. The amount of absorbed radiation depends on the quality of the glass, its purity, the material from which the window sashes are made, their thickness and dimensions. Through a window with single glazing, about half of the radiation falling on its surface penetrates into the room ( 40-58 percent), with double - about one third ( 23-40 percent).

As you move away from the window, the degree of ultraviolet irradiation decreases. When passing through a window glass, not only the intensity of sunlight is weakened, but also its spectral composition changes somewhat. Dirty glass further reduces the illumination of the room, more strongly affects the spectral composition of the sun's rays penetrating into the room. They are capable of absorbing more than 55 percent of the light falling on glass and most of the ultraviolet rays. It is necessary to constantly monitor the cleanliness of window glass and frames, if possible, open windows in the room more often. In addition to the beneficial effect on the human body, ultraviolet rays have another very important property - they are able to destroy microorganisms, including pathogens.

For decades, daylight has been viewed from an aesthetic point of view as one of the interior design tools with the pleasant bonus of a beautiful view from the window. However, recent research shows that the role of daylight is much more global - it is vital to our health and wellness.

We do not think about its properties and about the side effects that it brings to us. Many people do not realize that the feeling of fatigue at work or poor focus of vision depends on the illumination of the room, because this is not always obvious.

Lack of illumination affects the functioning of the human visual apparatus, the optic-vegetative system, the psyche, its emotional state, fatigue the central nervous system, which makes the person irritable. Sunlight (daylight) has a relaxing effect on the muscles around the eyes, stimulates the iris and nerves of the eyes, and increases blood circulation.

Research has shown a positive correlation between serotonin synthesis and total hours of sunlight during the day. Autopsies show that serotonin levels are higher in summer than in winter.

Too dim lighting spoils your vision and makes you fall asleep on the go, too bright lighting tires you (a common symptom is headache due to overexertion of the eye muscles). The best option is moderate-intense lighting, in which you can see everything perfectly, but your eyes are still comfortable.

Illuminance is the amount of light falling per unit area, measured in Lux. During the day, outdoor illumination typically ranges from 2,000 to 100,000 lux! European standard for lighting work spaces recommends the following illumination values:

Illumination	Appointment
300 lux	everyday office work that does not require looking at small details
500 lux	reading, writing and working at the computer
500 lux	lighting of meeting rooms
750 lux	technical drawing

There is evidence that the wrong level of illumination can cause headaches, fatigue, visual impairment and other troubles.

To achieve this effect, you can use a simple technique - combine general and local light source... The general light should be diffused, unobtrusive, the local light should be 2-3 orders of magnitude more intense than the general one. It is highly desirable that the local light be adjustable and directional. In general light, you can socialize, relax, do household chores or work that does not strain your eyes. If your activity requires the involvement of the eyes, vision, you can turn on local lighting, pick up.

Light is a natural condition of life, providing perception of the surrounding world. In order not to harm your health, you need to know how excessive illumination affects vision. Artificial light has merged so much with the modern way of life that people simply do not notice it anymore. However, this is the main factor that affects visual function.

How does lighting affect vision?

Solar

People see the world with the help of two types of light - natural (solar) and artificial. Sunlight is preferable because it has a beneficial effect on the human body and the organs of vision. Solar radiation is divided into two parts:

• visible - ultraviolet;
• invisible - infrared.

Infrared radiation is thermal. Ultraviolet - has a positive effect on the human body and causes an erythemal effect (sunburn). However, if the intensity of the rays is high, burns may appear on the skin. When it enters the eyes, intense ultraviolet radiation can burn the retina of the eye, which contributes to the deterioration or loss of vision.

Artificial

Heating and chemical reactions occur inside the unprotected eye.

Ultraviolet rays are also formed during the operation of artificial lighting equipment. These include the following devices and technical factors:

• electric arc;
• quartz lamps;
• electric and gas welding;
• laser installations;
• erythema lamps.

To protect your eyes from ultraviolet rays, you must wear protective goggles in strong light.

For artificial illumination, fluorescent lamps and incandescent lamps are used. The properties and condition of the eyes are influenced by energy-efficient lighting devices. When using them, an additional load on the organs of vision is carried out, causing rapid fatigue of the eye muscles. When an energy-saving lamp is used, it flickers, negatively affecting the eyes, and leading to a gradual deterioration in vision. As a result, the eyes turn red, dry, or, conversely, watery.

Some artificial light sources can create visual illusions. Strong light reflections from glossy surfaces, mirrors and glasses can cause considerable harm to human vision. Glare distracts attention, strains eyesight, it is difficult to focus on a specific subject. Therefore, light, matte surfaces that reflect radiation are more useful for the eyes.

What is the most favorable lighting?

Reading in daylight is most helpful.

The best condition for the organs of vision is light from the sun, but not too bright, but slightly diffused. However, it is not always enough due to such factors:

• When you stay indoors, the level of illumination of the space changes throughout the day, as the sun moves relative to the location of the person.
• In the cold season - from late autumn to mid-spring - natural light is too dim.

What should it be?

Therefore, during the day, the sun's rays are used for the background, which must be supplemented with artificial local illumination. The best option is moderate-intensity illumination, in which everything is visible and comfortable for the eyes. To achieve the optimal effect, two types of lighting are combined - general and local. General should be unobtrusive, scattered, local - much more intense.

It is desirable that the local lighting is directed and regulated. In general, you can deal with household issues, relax, communicate or do work for which you do not need to strain your eyes. If the activity requires the involvement of the eyes, you can turn on the local source of illumination and select the required intensity - one for working at a PC, another when reading.

The lighting intensity is different for each type of work.

Intensive lighting is recommended only when visual acuity is needed - you need to read something, count, write, etc. In other cases, you should give preference to diffused general illumination with a natural white-yellowish tint. During the day it is the sun's rays, in the dark - a ceiling lamp or other source. Work and living spaces should be properly lit, depending on the type of activity. All these points must be taken into account both for residential premises and for organizing lighting in workplaces.

Among the environmental factors that affect the body, light takes one of the first places. Light affects not only the organ of vision, but also the entire body as a whole. The idea of ​​the integrity of the organism, clearly expressed in the works of I.P. Pavlova, is confirmed by the reactions of the body in response to exposure to light. Light as an element of the human living environment is one of the main factors of the most important biomedical problem of our time - the organism and the environment. Under the influence of light, the physiological and mental reactions of the body are rebuilt.

Numerous studies of the effect of natural light on the human body have established that light affects various physiological processes in the body, promotes growth, activates metabolic processes, and increases gas exchange.

Light - visible radiation - is the only eye irritant that causes visual sensations that provide visual perception of the world. However, the effect of light on the eye is not limited only to the aspect of vision - the appearance of images on the retina and the formation of visual images. In addition to the main process of seeing, light also induces other important reflex and humoral reactions. Acting through an adequate receptor - the organ of vision, it causes impulses that propagate along the optic nerve to the optic region of the cerebral hemispheres (depending on the intensity), excites or depresses the central nervous system, rebuilding physiological and mental reactions, changing the general tone of the body, maintaining an active state ...

Visible light also affects immune and allergic reactions, as well as various metabolic parameters, changes the level of ascorbic acid in the blood, in the adrenal glands and the brain. It also acts on the cardiovascular system. Recently, the humoral influence of nervous excitement has also been established, which occurs during light irritation of the eye.

The bactericidal effect of ultraviolet rays, which are part of the spectrum of sunlight, is of particular hygienic importance. Under the influence of ultraviolet rays, the development of bacteria is delayed, and with a sufficiently long exposure, the bacteria die.

The role of the sun's radiant energy in the formation of a growing organism is especially great. By activating exchange processes, it promotes proper growth and development. Ultraviolet rays, converting provitamin D in the child's skin from an inactive state to an active one, provide normal bone formation. Good lighting also has a psychological effect; an abundance of light creates an emotionally upbeat, joyful mood.

Unfavorable lighting conditions cause a deterioration in general well-being, a decrease in physical and mental performance. Back in 1870, F.F.

Depending on the spectral composition, light can have an exciting effect and enhance the feeling of warmth (orange-red), or, conversely, calming (yellow-green), or enhance inhibitory processes (blue-violet).

This is used in the aesthetic design of industrial premises, painting equipment and walls: cold colors - at high temperatures and the presence of heat sources, in hot climates. Warm colors - in case of low temperatures, the need for a tonic effect of the working environment on workers. The most widely used color is green, which has a beneficial psychological effect.

The issues of rational organization of industrial lighting are not accidentally referred to the chapter "Protection of workers from harmful production factors". With insufficient illumination and poor quality lighting, the state of a person's visual functions is at a low initial level, visual fatigue increases in the process of performing work, the risk of industrial injuries increases, and labor productivity deteriorates.

According to statistics, on average, for various types of production activities, the number of accidents associated with unsatisfactory lighting is 30 ... 50% of the total.

Now, in the age of scientific and technological progress, in the most versatile fields, sources of radiant energy are widely used. In this regard, a person is exposed to natural and artificial sources of radiant energy with very different spectral characteristics and an extremely wide range of intensity: from 100,000 lux and more during the day in direct sunlight to 0.2 lux at night in the light of the moon.

The lack of natural light is associated with the phenomenon of "light starvation".

Light starvation is a condition of the body caused by a deficiency of ultraviolet radiation and manifested in metabolic disorders and a decrease in the body's resistance.

In addition, prolonged work in a room without natural light can have an adverse psychophysiological effect on personnel due to the lack of communication with the outside world, a sense of the enclosure of space.

To compensate for the ultraviolet deficiency, long-acting UV irradiators (combined with lighting devices) and short-term irradiators (photoariums) are used.

In rooms without natural light, gas-discharge light sources with a spectral composition close to natural, dynamic lighting devices are used for lighting, and special architectural techniques are used that simulate natural lighting (stained-glass windows, false windows, etc.).

Any work (like reading) can be done in a very wide range of light levels. However, its efficiency (reading speed) will change as shown in the figure.

influence light illumination organism human

Rice.

Up to a certain level of illumination, the work cannot be performed (the text is not visible, the reading speed will be equal to zero), then the efficiency of visual work increases and at some point reaches a maximum.

A further increase in illumination does not lead to an increase in efficiency (the reading speed does not change). The illumination corresponding to this value (the saturation point of the curve) is called the optimal illumination.

Many people think that mixed lighting is harmful to the eyes. However, this is not quite true. Mixed lighting consists of different wavelengths, which makes it less desirable than, for example, sufficient natural lighting. But it does not have a negative effect on the human body.

It is harmful to perform visual work with insufficient level of natural light, in which case mixed lighting will favor visual functions. Therefore, you should turn on the electric light without waiting until it gets completely dark.

15 Aug 2016

Most people spend their working day under artificial lighting. At the same time, during the day, a person can experience both bursts of activity and fatigue. This is because our biological clock and light are inextricably linked. It is worth noting that today bio-lighting technologies have been developed that allow you to control a person's biorhythms to increase his performance and improve well-being.

The effect of lighting on the human body

"Bad light makes a person unhappy." This idea of ​​the German designer Ingo Maurer has repeatedly found confirmation in research conducted by scientists. The influence of lighting on human health cannot be underestimated: low-quality light negatively affects the visual apparatus, causes overwork, discomfort, migraines, insomnia, and reduces performance.
Light has one more important property - to influence our biorhythms. It is known that in natural light, human activity is higher than in artificial light. In sunny weather, people report a higher performance than on a cloudy day. In winter, when daylight hours are shorter, we are less productive than in summer. Exposure to light on a person triggers a reaction of a special light-sensitive photopigment in the eye, which, in turn, can affect our circadian cycles.

What are circadian cycles?

The circadian cycle is called the daily change in biological processes in the human body. This cycle includes periods of sleep and wakefulness, activity and relaxation, productivity and fatigue. The change in biological rhythms is due to the action of hormones: melatonin is responsible for sleep, cortisol for activity, dopamine for mood, etc. During the day, the level of these hormones changes, which leads to a natural change in biorhythms. A healthy circadian cycle ensures well-being, vitality, mental and physical activity, and adequate sleep.

Circadian rhythm manifestations

The daily circadian rhythm is expressed in the change in the phases of the recovery activity of all organs and systems of a person - heart, brain, nervous system, metabolism. The change in rhythms is most clearly demonstrated by periods of sleep and wakefulness. Other manifestations of circadian rhythms are less noticeable, but they are reflected in a person's behavior, in his state of health, in periods of activity and fatigue. So, it was found that the working capacity has several peaks during the day, at 10, 15 and 17 hours, and at 22-23 hours the body experiences a physiological decline and rebuilds to a rest mode.

Effects of daylight on circadian cycles

Circadian cycles are inextricably linked with lighting. In the evening, with a decrease in the intensity of natural light, the activity of the hormone melatonin, which is responsible for relaxing the body, increases. The level of activity decreases, the person experiences fatigue and drowsiness. With dawn, exposure to light increases, melatonin levels decrease, and the body gradually enters an activity phase. Its decline, decreased mood, a feeling of drowsiness and lethargy, deterioration of health in the autumn-winter period are explained by late dawns and lack of sunlight, since these factors provoke an increase in melatonin levels and a decrease in the production of the "vigor hormone" cortisol. Thus, the intensity of daylight and the biorhythms of the human body are in direct relationship. This fact makes it possible to talk about the possibility of harmonizing circadian cycles with the help of lighting.

Controlling biorhythms with office lighting

Most of the day, a person is forced to work under artificial lighting conditions. In many offices and factories, there is little sunshine even in summer. In winter, when daylight hours are short, working hours almost always start before sunrise and end after sunset. Under these conditions, artificial light constantly suppresses the body's production of melatonin. A person does not feel sleepy, but his periods of activity are less productive: concentration of attention decreases, mood worsens. The influence of standard artificial lighting on the conditions of human activity disrupts the natural course of biorhythms and negatively affects health and performance.
The hormones that cause circadian rhythms can be safely regulated by high-quality lighting. Biologically and emotionally effective light systems successfully solve this problem. They are designed to improve the physical, emotional and health of a person and help him to more efficiently solve work problems.
Lighting Technologies has developed innovative lighting solutions for workspaces. We are talking about controlling the color temperature of lighting devices: it is adjusted based on a specific working situation - "negotiations", "rest", etc. It is known that a neutral color creates comfortable conditions for solving standard tasks. The cold temperature of the light increases the level of activity, promotes concentration and therefore can be used in cases where complete dedication is required from employees: at important meetings or creative storms. The warm color of the lighting is necessary for periods of rest, when the human body can recover its strength. A biologically and emotionally efficient lighting system allows for a thoughtful and safe health effect of light. Such light takes into account the circadian rhythms of a person, helps to correctly correct them and effectively spend energy during the working day.
Biologically and emotionally efficient lighting holds great promise in a variety of industries. Given the climatic features of our country with a characteristic sun deficit in some periods, it is the installation of such lighting that will compensate for the lack of natural light. Positive results on the effect of lighting on human health can be obtained in the conditions of offices, industrial production due to the increase in the efficiency of employees. Human Centric Lighting will be effective in rehabilitation facilities where patients may be in confined spaces for a long time and lack daylight.
Learn more about biologically and emotionally efficient lighting at.

A large number of controversies regularly persist around light sources of varying intensities. Natural light does not raise questions, and various types of modern lamps are regularly illuminated by specialists in the field of anatomy, hygiene and sanitation, who are trying to refute the current norms, distort or refute the standards given by the ministries. It is possible that this is due to a large number of myths or the results of individual intolerances. In the 1950s, there was already a social movement in a number of Western countries that said that the combination of the sun's rays and an incandescent lamp was harmful to human skin. The influence of light on a person has not been fully studied, but no negative manifestations have yet been associated with this external factor.

In order for the lamp to work in this range, it is necessary to make it for these purposes. For example, infrared devices are used in medicine and for drying varnishes, and ultraviolet for checking bank notes, special glues and growing plants. None of these areas will accept conventional lamps. So you don't even need to think about it. In the same way, repeated false arguments arose about the radioactivity of LEDs, various harmful fumes and other absurd factors. Modern lamp manufacturers take into account a huge number of safety factors. It is hard to believe that someone could apply such a significant pathogenic factor on a planetary scale.

Possible carcinogenic factors

Yes, the sun can actually trigger the development of skin cancer. This must be taken into account for people with a large number of moles. But it is almost impossible to create such an intensity of all radiation spectra in a room with the help of lamps. We underestimate the brightness of the celestial body, and yet it brings down a huge amount of energy on our planet every day. It is impossible to compensate for this enough to provoke negative processes in the skin.

With the right choice of lighting devices, the entire team will work cheerfully in any weather. If lamps oppress the human psyche, then you don't even need to think about a high-quality workflow. In Western countries, this is a subject of serious study, because there they practically managed to get rid of the syndrome of chronic fatigue and headache in employees of enterprises during a normalized working day.

About yellow and white spectra

The effect of light on human health is completely independent of the spectrum. This is purely a matter of personal preference or convenience. Small details will be better distinguished in the cold spectrum, but eyes get tired of it quickly. The yellow or warm spectrum is necessary for long-term comfortable stay in the room. It is more suitable for apartments and houses. It is also necessary to understand that insufficient brightness too strongly oppresses the mental component in every person. It is not for nothing that the lights in prison cells are dimmed so that prisoners never even have the thought of running away or rebelling. Too much light affects the retina of the eye. From a constant concentration, blood pressure can rise significantly. It is the wrong selection, and not the light itself, that has the most important effect on the organs of vision. I would especially like to ask parents to choose the right table lamp for their child.

What makes us talk about the dangers of light

Now, according to experts, more than half of the total turnover of goods in the world is accounted for by cheap copies and fakes. Therefore, there is no need to be surprised if a lamp produced without any standard produces harmful radiation. Another factor can be considered a real revelry of the yellow press, including on the worldwide network. Any person without appropriate education or qualifications is trying to earn a big name for himself out of the blue. Any facts, false studies will be presented in order to "expose the global conspiracy." We can expertly state that the influence of light on a person will be insignificant if the selection of lighting devices is made by specialized specialists.